U.S. patent application number 16/804239 was filed with the patent office on 2020-06-25 for passenger conveyor.
This patent application is currently assigned to Kone Corporation. The applicant listed for this patent is Kone Corporation. Invention is credited to Janne LAINE, Jorma MUSTALAHTI, Raimo PELTO-HUIKKO, Tarvo VIITA-AHO.
Application Number | 20200198935 16/804239 |
Document ID | / |
Family ID | 65526241 |
Filed Date | 2020-06-25 |
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United States Patent
Application |
20200198935 |
Kind Code |
A1 |
VIITA-AHO; Tarvo ; et
al. |
June 25, 2020 |
PASSENGER CONVEYOR
Abstract
The invention relates to a passenger conveyor, such as an
escalator or autowalk, comprising a band of conveying elements; a
diverting wheel for diverting the passage of the band of conveying
elements and/or a traction member thereof and a brake for braking
rotation of the diverting wheel. The brake comprises a screw member
having a conical threaded external rim; a nut member having a
conical threaded internal rim, the screw member and nut member
being screwed together, one of said screw member and nut member
being connected with the diverting wheel for being driven by the
diverting wheel. The brake further comprises a stopping device for
stopping rotation of the other of said screw member and nut
member.
Inventors: |
VIITA-AHO; Tarvo; (Helsinki,
FI) ; MUSTALAHTI; Jorma; (Hyvinkaa, FI) ;
PELTO-HUIKKO; Raimo; (Helsinki, FI) ; LAINE;
Janne; (Helsinki, FI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kone Corporation |
Helsinki |
|
FI |
|
|
Assignee: |
Kone Corporation
Helsinki
FI
|
Family ID: |
65526241 |
Appl. No.: |
16/804239 |
Filed: |
February 28, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/FI2017/050610 |
Aug 30, 2017 |
|
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|
16804239 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B66B 29/00 20130101;
B66B 23/026 20130101; B66B 23/024 20130101; B66B 21/04 20130101;
B66B 21/10 20130101; F16D 63/006 20130101; F16D 2121/20 20130101;
F16D 2125/28 20130101 |
International
Class: |
B66B 29/00 20060101
B66B029/00; B66B 21/04 20060101 B66B021/04; B66B 21/10 20060101
B66B021/10; F16D 63/00 20060101 F16D063/00 |
Claims
1. A passenger conveyor, such as an escalator or autowalk,
comprising a band of conveying elements; a diverting wheel for
diverting the passage of the band of conveying elements and/or a
traction member thereof; a brake for braking rotation of the
diverting wheel, wherein the brake comprises a screw member having
a conical threaded external rim; a nut member having a conical
threaded internal rim, the screw member and nut member being
screwed together, one of said screw member and nut member being
connected with the diverting wheel for being driven by the
diverting wheel, a stopping device for stopping rotation of the
other of said screw member and nut member.
2. A passenger conveyor according to claim 1, wherein the screw
member and nut member are rotatable together by the diverting
wheel.
3. A passenger conveyor according to claim 1, wherein said one of
said screw member and nut member is said screw member and said
other of said screw member and nut member is said nut member.
4. A passenger conveyor according to claim 1, wherein the screw
member and nut member have been pre-tightened together by screwing
of the screw member into the nut member, preferably with at least 1
Nm torque.
5. A passenger conveyor according to claim 1, wherein the screw
member and nut member are tightenable together to engage more
firmly with each other, by screwing of the screw member deeper into
the nut member.
6. A passenger conveyor according to claim 1, wherein rotation of
the diverting wheel in its first rotation direction is arranged to
cause screwing of the screw member deeper into the nut member, if
the stopping device has stopped rotation of said other of said
screw member and nut member.
7. A passenger conveyor according to claim 1, wherein the band of
conveying elements comprises an inclined conveying section for
conveying passengers standing on the conveyor elements at an
inclined angle upwards or downwards.
8. A passenger conveyor according to claim 6, wherein said first
direction is the rotation direction in which the diverting wheel
rotates when the conveying elements of the inclined section that
are accessible to stand on by passengers move at an inclined angle
downwards.
9. A passenger conveyor according to claim 1, wherein said one of
said screw member and nut member is connected with the diverting
wheel by a connection transmitting rotation between the two in two
opposite rotation directions.
10. A passenger conveyor according to claim 1, wherein said one of
said screw member and nut member is fixed on the diverting wheel or
a shaft on which the diverting wheel is mounted.
11. A passenger conveyor according to claim 1, wherein the nut
member is surrounded by an empty space outside it in radial
direction, in particular whereto it is free to radially expand when
tightened together with the screw member and/or the screw member
has an empty inside space, in particular whereto it is free to
radially expand when tightened together with the screw member.
12. A passenger conveyor according to claim 1, wherein the
passenger conveyor comprises a control arrangement arranged to
control operation of the stopping device.
13. A passenger conveyor according to claim 1, wherein the stopping
device comprises at least one stopping member movable to act on the
other of said screw member and nut member for stopping rotation
thereof, for thereby causing relative rotation between the screw
member and nut member.
14. A passenger conveyor according to claim 12, wherein the control
arrangement is arranged to control movement of the at least one
stopping member.
15. A passenger conveyor according to claim 1, wherein said other
of said screw member and nut member comprises a cogged rim, and
said stopping member is movable into rotational path of at least
one of the cogs of the cogged rim.
16. A passenger conveyor according to claim 12, wherein the control
arrangement comprises an electrical controller configured to
control the stopping device over an electrical bus.
17. A passenger conveyor according to claim 16, wherein the
electrical controller is configured to activate the stopping device
to stop rotation of the other of said screw member and nut member,
in particular when one or more predetermined criteria are met,
preferably including overspeed is detected in one or more of moving
parts of the conveyor.
18. A passenger conveyor according to claim 1, wherein the stopping
device comprises an electrically controlled actuator, such as a
solenoid.
19. A passenger conveyor according to claim 18, wherein the
electrically controlled actuator is suitable for actuating the
stopping member to act on the other of said screw member and nut
member for stopping rotation thereof.
20. A passenger conveyor according to claim 14, wherein the control
arrangement comprises a cam wheel and a pendulum pivotal around a
fulcrum, the pendulum comprising a roller spring-tightened to run
along the cam wheel, the roller being arranged to be moved radially
outwards by the cams of the cam wheel, and returned radially
inwards by a spring mechanism, and the roller is arranged to loose
contact with the cam wheel such that the pendulum turns to such a
position that a stopping member thereof extends into path of a cog
of the aforementioned cogged rim if rotational speed of the cam
wheel exceeds a limit.
21. A passenger conveyor according to claim 1, wherein the traction
member is a chain.
22. A passenger conveyor according to claim 1, wherein the
diverting wheel is a sprocket around and against which the traction
member and/or conveying elements pass.
23. A passenger conveyor according to claim 1, wherein the
passenger conveyor is an escalator and said conveying elements are
steps.
24. A passenger conveyor according to claim 1, wherein the
passenger conveyor comprises a first brake, which is the main brake
of the passenger conveyor, and a second brake, which is an
auxiliary brake of the passenger conveyor, said brake being said
second brake.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of PCT International
Application No. PCT/FI2017/050610 which has an International filing
date of Aug. 30, 2017, the entire contents of which are
incorporated herein by reference
FIELD OF THE INVENTION
[0002] The invention relates to stopping of movement of a passenger
conveyor, such as an escalator or a moving ramp.
BACKGROUND OF THE INVENTION
[0003] Escalators and moving ramps are passenger conveyors, each of
which typically comprises an endless band of conveying elements,
such as steps or pallets for supporting the load to be transported,
i.e. a person. The conveying element typically comprises guide
rollers and a tread member with a tread surface on which a person
can stand. The conventional passenger conveyors furthermore
comprise elongated guide rails for guiding and supporting the guide
rollers of the conveying elements. The conveying elements are
typically connected to each other. They are typically connected to
each other by a traction member such as a chain. However,
alternatively they can be directly connected to each other, which
is the case in some moving ramps particularly. In this case a
separate traction member may not be needed at all as the conveying
members can transmit traction to each other directly. In the first
mentioned type, the drive member can be on one or both lateral
sides of each conveying element, for instance. It is typical that
one guide roller of the step is coupled with a chain link of the
chain. Thereby, the chain becomes guided by the guide rollers as
well. The passenger conveyors are typically arranged to divert the
path of its moving parts at its upper and lower end by a diverting
wheel, which diverting wheel diverts passage of the chain and the
conveying elements.
[0004] For moving the conveying elements, the passenger conveyor
comprises typically a machinery comprising a motor, and for
stopping movement of the conveying elements, the machinery can
comprise a main brake. It may be that the passenger conveyor also
needs to have an auxiliary brake for preventing certain special
conditions. Such a special condition is particularly uncontrolled
rushing of the people conveyor, which may be caused in free
rotation of the main shaft, for instance. Such rushing in downwards
direction can take place in passenger conveyors due to passenger
weight when the endless band of conveying elements comprises an
inclined conveying section for conveying passengers standing on the
conveyor elements at an inclined angle. Such a rushing may also be
caused by a failure in some part of the machinery, such as braking
of the main brake or failure of the motor encoder. A drawback of
known passenger conveyors has been that they have not had a
reliable, compact and simple brake suitable for serving as an
auxiliary brake for stopping of the passenger conveyor in such
situations.
BRIEF DESCRIPTION OF THE INVENTION
[0005] The object of the invention is to introduce a new passenger
conveyor, which is improved in terms of its stopping function. An
object is to introduce a solution by which one or more of the above
defined problems of prior art and/or drawbacks discussed or implied
elsewhere in the description can be solved. An object is to
introduce an improved solution which is structurally simple due to
having small number of components, compact, produces a great
braking force, and can stop movement of the passenger conveyor
reliably and swiftly.
[0006] It is brought forward a new passenger conveyor, such as an
escalator or an autowalk, comprising an endless band of conveying
elements. The passenger conveyor may also comprise an endless
traction member. The passenger conveyor further comprises a
diverting wheel for diverting the passage of the band of conveying
elements and/or the aforementioned traction member thereof, as well
as a brake for braking rotation of the diverting wheel. The brake
comprises a screw member having a conical threaded external rim,
and a nut member having a conical threaded internal rim. The
threads of the screw and nut are particularly counterparts for each
other. The screw member and nut member are screwed together, in
particular such that the nut member is around the screw member,
their threads engaging each other. One of said screw member and nut
member is connected with the diverting wheel for being driven by
the diverting wheel. The passenger conveyor further comprises a
stopping device for stopping rotation of the other of said screw
member and nut member, in particular for thereby causing relative
rotation between the screw member and nut member when said one of
said screw member and nut member rotates driven by the diverting
wheel. With this solution one or more of the above mentioned
objects can be achieved. Preferable further details of the
passenger conveyor are introduced in the following, which further
details can be combined with the passenger conveyor individually or
in any combination.
[0007] In a preferred embodiment, the screw member and nut member
are rotatable together, in particular as one unit, by the diverting
wheel. Preferably, this is implemented such that said one of said
screw member and nut member connected with the diverting wheel for
being driven by the diverting wheel is arranged to transmit
rotation to the other of said screw member and nut member,
preferably at least partially via their threaded engagement, such
that they are rotatable together, in particular as one unit, by the
diverting wheel. The threaded engagement can be simply made so
tight, e.g. by pre-tightening, that it transmits rotation between
said two members. Also, additional or alternative means could of
course be used for making the screw member and nut member rotatable
together.
[0008] In a preferred embodiment, said one of said screw member and
nut member is said screw member and said other of said screw member
and nut member is said nut member. This could alternatively be vice
versa.
[0009] In a preferred embodiment, the screw member and nut member
have been pre-tightened together by screwing of the screw member
into the nut member, preferably with at least 1 Nm torque.
[0010] In a preferred embodiment, the screw member and nut member
are tightenable together, to engage more firmly with each other, by
screwing of the screw member deeper into the nut member, i.e.
towards the tip of the conical threaded internal rim.
[0011] In a preferred embodiment, rotation of the diverting wheel
in its first rotation direction is arranged to cause screwing of
the screw member deeper into the nut member, if the stopping device
has stopped rotation of said other of said screw member and nut
member.
[0012] In a preferred embodiment, the band comprises an inclined
conveying section for conveying passengers standing on the conveyor
elements at an inclined angle upwards or downwards.
[0013] In a preferred embodiment, said first direction is the
rotation direction in which the diverting wheel rotates when the
conveying elements of the inclined section that are accessible to
stand on by passengers move at an inclined angle downwards.
[0014] In a preferred embodiment, said one of said screw member and
nut member is connected with the diverting wheel by a connection
transmitting rotation between said one of said screw member and nut
member and the diverting wheel in two opposite rotation
directions.
[0015] In a preferred embodiment, said one of said screw member and
nut member is fixed, in particular immovably, on the diverting
wheel or the shaft on which the diverting wheel is mounted.
[0016] In a preferred embodiment, the nut member is surrounded by
an empty space outside it in radial direction whereto it is free to
radially expand when tightened together with the screw member
and/or the screw member has an empty inside space inside it in
radial direction whereto it is free to radially expand when
tightened together with the screw member. Preferably, the nut
member and screw member are both cylindrical.
[0017] In a preferred embodiment, the passenger conveyor comprises
a control arrangement arranged to control operation of the stopping
device.
[0018] In a preferred embodiment, the stopping device comprises at
least one stopping member movable to act on the other of said screw
member and nut member for stopping rotation thereof, for thereby
causing relative rotation between the screw member and nut member,
when said one is rotated.
[0019] In a preferred embodiment, the control arrangement is
arranged to control movement of the at least one stopping
member.
[0020] In a preferred embodiment, said other of said screw member
and nut member comprises a cogged rim, and said stopping member is
movable into rotational path of at least one of the cogs of the
cogged rim.
[0021] In a preferred embodiment, the control arrangement for
controlling movement of the at least one stopping member comprises
an electrical controller configured to control the stopping device,
e.g. over an electrical bus.
[0022] In a preferred embodiment, the controller is configured to
activate the stopping device to stop rotation of the other of said
screw member and nut member, in particular when one or more
predetermined criteria are met, preferably including overspeed
detected in one or more of moving parts of the conveyor.
[0023] In a preferred embodiment, the stopping device comprises an
electrically controlled actuator, such as a solenoid. Preferably,
the electrically controlled actuator, such as a solenoid as
mentioned, is suitable for actuating the stopping member to act on
the other of said screw member and nut member for stopping rotation
thereof, for thereby causing relative rotation between the screw
member and nut member, when said one of said screw member and nut
member is rotated. The electrically controlled actuator can be
suitable for actuating the stopping member to move into rotational
path of at least one of the cogs of the cogged rim, for
example.
[0024] In a preferred embodiment, the control arrangement for
controlling movement of the at least one stopping member comprises
a cam wheel and a pendulum pivotal around a fulcrum, the pendulum
comprising a roller spring-tightened to run along the cam wheel,
the roller being arranged to be moved radially outwards by the cams
and returned radially inwards by a spring mechanism, and the roller
is arranged to loose contact with the cam wheel, in particular
thrown by a cam of the cam wheel, such that the pendulum turns to
such a position that a stopping member thereof extends into path of
a cog of the aforementioned cogged rim if rotational speed of the
cam wheel exceeds a limit. An advantage of the cam wheel operated
pendulum is that it provides a mechanical means which are
relatively fail safe and which can monitor rotational speed
reliably.
[0025] In a preferred embodiment, the passenger conveyor is an
escalator or an autowalk.
[0026] In a preferred embodiment, the passenger conveyor comprises
a motor for moving the band of conveying elements.
[0027] In a preferred embodiment, the traction member is connected
with the conveying elements for transmitting traction force to the
conveying elements.
[0028] In a preferred embodiment, the aforementioned traction
member is a chain.
[0029] In a preferred embodiment, the diverting wheel is a sprocket
around and against which the traction member and/or conveying
elements pass.
[0030] In a preferred embodiment, the passenger conveyor is an
escalator and said conveying elements are steps.
[0031] In a preferred embodiment, each of the conveying elements
comprises a tread member with a tread surface on which a person can
stand.
[0032] In a preferred embodiment, the nut member and the screw
member are made of metal.
[0033] In a preferred embodiment, the cone angle of the conical
threaded external rim of the screw member and the cone angle of the
conical threaded internal rim of the nut member are each in the
range of 1-20 degrees, most preferably in the range of 5-15
degrees. The cone angles of this kind facilitates that the
tightening progresses advantageously. Preferably, said cone angles
of the screw member and the nut member are the same or at least
substantially the same.
[0034] In a preferred embodiment, the rise angle of the threads of
the screw member 7 and the rise of the threads of the nut member
are in the range of 1-10 degrees, more preferably in the range of
1-5 degrees, most preferably in the range of 1-3 degrees.
Preferably, the rise angles of the threads of the screw member 7
and the nut member are the same or at least substantially the same.
The rise of this kind facilitates that the tightening progresses
advantageously. In a preferred embodiment, the passenger conveyor
comprises a first brake, which is the main brake of the passenger
conveyor, and a second brake, which is an auxiliary brake of the
passenger conveyor, said brake being said second brake.
[0035] In a preferred embodiment, the band of conveying elements
comprises an inclined conveying section for conveying passengers
standing on the conveyor elements at an inclined angle upwards or
downwards.
[0036] In a preferred embodiment, said screw member and nut member
are coaxial with each other, and preferably also with the diverting
wheel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] In the following, the present invention will be described in
more detail by way of example and with reference to the attached
drawings, in which
[0038] FIG. 1 illustrates a preferred embodiment of the passenger
conveyor according to the invention.
[0039] FIG. 2 illustrates preferred details of a brake of the
passenger conveyor according to the invention.
[0040] FIG. 3 illustrates cross section A-A of FIG. 2.
[0041] FIG. 4 illustrates structure of the nut member and the screw
member fitted together.
[0042] FIGS. 5-7 illustrate preferred details for controlling
operation of the stopping device of FIG. 2.
[0043] FIG. 8 illustrates a block diagram of a preferred control
arrangement for controlling operation of the stopping device of
FIG. 2.
[0044] The foregoing aspects, features and advantages of the
invention will be apparent from the drawings and the detailed
description related thereto.
DETAILED DESCRIPTION
[0045] FIG. 1 illustrates a passenger conveyor 1, in particular an
escalator, comprising an endless band 2 of conveying elements 3,
the band 2 comprising an inclined conveying section 2a for
conveying passengers standing on the conveyor elements 3 at an
inclined angle upwards or downwards. The passenger conveyor 1
moreover comprises a diverting section 2b for diverting the passage
of the band 2 of the conveying elements 3.
[0046] In the presented preferred embodiment, the passenger
conveyor 1 is an escalator where the conveying elements are
connected to each other by an endless traction member, which is in
the presented case a chain 5 as presented more precisely in FIG.
2.
[0047] The passenger conveyor 1 comprises a diverting wheel 4,
which is in the presented preferred embodiment a step chain
sprocket wheel, for diverting the passage of the band 2 of
conveying elements 3 and a traction member 5 thereof.
[0048] The passenger conveyor 1 moreover preferably comprises a
motor (not illustrated) for moving the band 2 of conveying elements
3. The motor can be arranged to rotate the diverting wheel 4,
whereby the traction member 5 can be moved by the motor for
producing traction on the conveying elements 3.
[0049] The passenger conveyor 1 moreover comprises a brake 6 for
braking rotation of the diverting wheel 4. FIG. 2 illustrates a
schematic presentation of the brake 6. The brake 6 comprises a
screw member 7 having a conical threaded external rim 7a, and a nut
member 8 having a conical threaded internal rim 8a. The threads of
the screw and nut are counterparts for each other, and the screw
member 7 and nut member 8 are screwed together, such that the nut
member is around the screw member, their threads engaging each
other. Said screw member 7 is connected with the diverting wheel 4
for being driven by the diverting wheel 4, and arranged to transmit
rotation to the nut member 7 mounted thereon, at least partially
via their threaded engagement, such that they are rotatable
together, in particular as one unit, by the diverting wheel 4.
Their engagement being established by the threaded rims, relative
rotation between them can be caused, which causes screwing of the
screw member 7 within the nut member 8. The brake 6 moreover
comprises a stopping device 9 for stopping rotation of the other of
said screw member and nut member 7,8, for thereby causing relative
rotation between the screw member 7 and nut member 8 if said screw
member 7 rotates driven by the diverting wheel 4.
[0050] Due to above described structure the screw member 7 and nut
member 8 are tightenable together, to engage more firmly with each
other, by screwing of the screw member 7 deeper into the nut member
8, i.e. towards the tip of the conical threaded internal rim. When
tightened together, the screw member 7 and nut member 8 do not
freely rotate relative to each other but they are stuck to each
other. Pre-tightening is arranged to be such that it suffices to
maintain the relative positioning of the screw member 7 and the nut
member 8 the same unless the stopping device 9 stops rotation of
the nut member 8, and the screw member 7 is rotated by the
diverting wheel 4.
[0051] Rotation of the diverting wheel 4 in its first rotation
direction D1 causes the screw member 7 to screw deeper into the nut
member 8, such that the screw member 7 and nut member 8 become
gradually tightened to be immovable relative to each other, if the
stopping device 9 has stopped rotation of said other of said screw
member and nut member 7,8. Said tightening occurs because of the
conical shape of the rims of the screw member 7 and the nut member
8 on which the threads are disposed. When these members 7,8 are
rotated relative to each other in tightening direction, the threads
of these members 7,8 guide the screw member deeper into the nut
member, but the screw member 7 cannot pass through the nut member 8
due to their conical shapes. Instead, the screw member 7 becomes
wedged incrementally tighter into the nut member 8 as the rotation
progresses. The threads of the screw member 7 and the nut member 8
engaging each other, there is friction between these members 7,8,
which resists their rotation relative to each other. Due to the
conical shape of the rims of the screw member 7 and the nut member
8 on which the threads are disposed, tightening of the screw member
7 and the nut member 8 increases the normal forces existing between
the screw member 7 and the nut member 8. Thereby the tightening
increases the friction forces between these parts which resist
their rotation relative to each other. Friction forces slow down
the relative rotation between these parts and eventually stops it
completely. Thus, the diverting wheel 4 becomes stopped as well.
Said first rotation direction D1 is preferably the rotation
direction in which the diverting wheel 4 rotates when the conveying
elements 3 of the inclined section that are accessible to stand on
by passengers move at an inclined angle downwards. Arrow 22 in FIG.
3 illustrates the direction in which the nut member 8 moves in said
tightening. Arrows 23 and 24 in FIG. 3 illustrate the direction in
which the screw member 7 and the nut member 8 preferably expand
when they are tightened strongly. For enabling such a deformation,
it is advantageous that the nut member 8 is surrounded by an empty
space I2 outside it in radial direction whereto it is free to
radially expand when tightened together with the screw member 7,
and/or that the screw member 7 has an empty inside space I1 inside
it in radial direction whereto it is free to radially expand when
tightened together with the nut member 8. The deformation
facilitates that the normal forces and friction between the screw
member 7 and the nut member 8 increases in an advantageous way. At
least part of the energy is transformed into heat due to friction.
The deformation may absorb part of the energy needed for braking.
Generally, the aforementioned deformation is advantageous as it
facilitates that the stopping is not extremely sudden.
[0052] As an alternative or in addition to the aforementioned
radial expansion of the one or both of the nut member 8 and the
screw member 7, the threads of the nut member 8 and/or the screw
member 7 are arranged to deform when the nut member 8 and/or the
screw member 7 are tightened together.
[0053] The cross section of both the screw member 7 and nut member
8 is such that the peaks of the threads of the screw member 7
extend along a line L1 oriented towards the central axis c of the
external rim of the screw member 7, and the peaks of the threads of
the nut member 8 extend along a line L2 oriented towards the
central axis c of the internal rim nut member 8, respectively. The
line is preferably straight which is the case in the embodiment
illustrated in FIG. 3. The line might however slightly differ from
straight. The aforementioned lines of the screw member 7 and nut
member 8 are preferably parallel or at least substantially
parallel.
[0054] Said screw member 8 is connected with the diverting wheel 4
by a connection transmitting rotation between the two in two
opposite rotation directions, said transmitting preferably being
rigid. This is preferably implemented such that the screw member 8
is fixed to the diverting wheel 4, e.g. by aid of one or more bolts
as presented in FIG. 3. Alternatively, this can be implemented such
that the screw member 8 is fixed to the shaft 11 on which the
diverting wheel 4 is rigidly connected.
[0055] In the preferred embodiments illustrated in FIGS. 1-4, the
stopping device 9 is such that it comprises a stopping member 9a
movable to act on the nut member 8 for stopping rotation thereof,
for thereby causing relative rotation between the screw member and
nut member, when said screw member 7 is rotated.
[0056] In the preferred embodiments illustrated in FIGS. 1-4, the
nut member 8 comprises a cogged rim, and said stopping member 9a is
movable into rotational path of at least one of the cogs 12 of the
cogged rim. Utilizing a cogged rim is advantageous structure due to
its simplicity, reliability and usability with different
alternative stopping members 9a, and with different means for
moving the stopping member 9a. However, a stopping member could of
course be arranged to stop the rotation of the nut member 8
differently than what is presented in context of the preferred
embodiments. For example, it is an alternative that frictional
engagement is utilized instead of the mechanical locking occurring
in the embodiment utilizing a stopping member movable into
rotational path a cog 12 of a cogged rim.
[0057] The passenger conveyor 1 preferably comprises a control
arrangement 18,20,21;13,15,16 arranged to control operation of the
stopping device 9. The aforementioned control arrangement
18,20,21;13,15,16 is arranged to control movement of the stopping
member 9a. FIGS. 5-8 illustrate preferred details for controlling
operation of the stopping device 9.
[0058] In the embodiment illustrated in FIG. 5, the control
arrangement 13,15,16 for controlling movement of the at least one
stopping member 9a comprises a cam wheel 13 rotated by the
diverting wheel 4, as well as a pendulum 14, which is pivotal
around a fulcrum 17. The cams of the cam wheel 13 are curved such
that a roller 15 can run along them. The pendulum comprises a
roller 15 spring-tightened to run along the rim of the cam wheel
13, the roller 15 being movable radially outwards, i.e. from the
rotation axis of the cam wheel 13, by the cams of the cam wheel 13
and returned radially inwards, i.e. towards the rotation axis of
the cam wheel 13, by a spring mechanism 16. If rotational speed of
the cam wheel 13 exceeds a limit, the roller 15 is arranged to
loose contact with the cam wheel 13, thrown by a cam of the cam
wheel 13, such that the pendulum turns to such a position that a
stopping member 9a thereof extends into path of a cog 12 of the
aforementioned cogged rim. Above the limit, the spring force of the
spring mechanism 16 is not anymore adequate to return the roller 15
radially inwards so swiftly that a contact with the cam wheel 13 is
maintained. The stopping member 9a extending into path of a cog 12
of a cogged rim of the nut member, further rotation of the cam
wheel 13 (at a speed exceeding said limit) will make the cog 12 of
a cogged rim of the nut member 8 and the aforementioned part 9a
collide, and stop the rotation of the nut member 8. This produces
relative rotation between nut member 8 and screw member 7 as
earlier described. FIG. 6 illustrates a condition where the
stopping member 9a extends into path of a cog 12 of a cogged rim.
The spring mechanism 16 is preferably such that it comprises at
least one spring connected between the pendulum 14 and a stationary
member of the conveyor 1, such as a stationary support member 17 of
the shaft 11 of the diverting wheel 4, for example.
[0059] In the embodiment illustrated in FIG. 7, the control
arrangement 18,20,21;13-16 for controlling movement of the at least
one stopping member 9a is otherwise in accordance with the
embodiment of FIGS. 5-6 but further comprises an electrical
controller 20 configured to control the stopping device 9 over an
electrical bus 21. The controller 20 is configured to activate the
stopping device 9 to stop rotation of the other of said screw
member and nut member 7,8, in particular when one or more
predetermined criteria are met, preferably including overspeed
detected in one or more of moving parts of the conveyor 1. In this
embodiment, the stopping device 9 comprises an electrically
controlled actuator 18, such as a solenoid.
[0060] The aforementioned electrically controlled actuator 18, such
as a solenoid, is arranged to actuate the stopping member 9a to act
on the nut member 8 for stopping rotation thereof, for thereby
causing relative rotation between the screw member and nut member,
when said screw 7 is rotated. In the presented embodiment
electrically controlled actuator 18 is arranged particularly to
actuate the stopping member 9a to move into rotational path of at
least one of the cogs 12 of the cogged rim. This is implemented
such that the electrically controlled actuator 18 is arranged to
actuate the stopping member 9a by pushing a lever 19 of the
pendulum 14 to pivot it such that the stopping member 9a moves into
rotational path of at least one of the cogs 12.
[0061] FIG. 8 illustrates a block diagram of the control
arrangement for controlling movement of the at least one stopping
member 9a, where it comprises an electrical controller 20
configured to control the stopping device 9 over an electrical bus
21.
[0062] Generally, the control arrangement for controlling movement
of the at least one stopping member 9a can be implemented also
without a cam-operated pendulum as presented in FIGS. 5-7. The cam
operation provides a relatively fail safe solution where rotation
speed becomes reliably monitored. However, its' presence is not
necessary. At simplest, the control arrangement can comprise an
actuator arranged to operate the stopping member 9a and controlled
by the electrical controller 20, the actuator preferably being then
a solenoid. The stopping member 9a can then be movable by linear
motion or pivotal around a fulcrum.
[0063] Preferably, the cone angle (x) of the conical threaded
external rim of the screw member 7 and the cone angle (y) of the
conical threaded internal rim of the nut member 8 are each in the
range of 1-20 degrees, most preferably in the range of 5-15
degrees, wherein the cone angle (x) is the angle between line L1
and the central axis c of the external rim of the screw member 7,
and the cone angle (y) is the angle between line L2 and the central
axis c of the internal rim of the nut member 8. The cone angles of
this kind provide that the tightening occurs progresses
advantageously. Preferably, said cone angles of the screw member 7
and the nut member 8 are the same or at least substantially the
same.
[0064] Preferably, the rise angle of the threads of the screw
member 7 and the rise of the threads of the nut member are in the
range of 1-10 degrees, more preferably in the range of 1-5 degrees,
most preferably in the range of 1-3 degrees. Preferably, the rise
of the threads of the screw member 7 and the nut member are the
same or at least substantially the same. The rise in millimeters
can be for example 1-5 mm/round, e.g. 3 mm/round.
[0065] Generally, the passenger conveyor 1 can be an escalator or
an autowalk. The aforementioned conveying elements 3 are steps if
the people mover is an escalator and pallets or a conveying belt if
the people mover is an autowalk. As mentioned, the band 2 can
comprise an inclined conveying section for conveying passengers,
who stand on the conveyor elements, at an inclined angle upwards or
downwards. In this case, the solution is particularly advantageous
as in this case the passenger conveyor has the risk of rushing
downwards due to gravity affecting on the passengers. Such an
inclined conveying section is comprised in escalators, and when the
passenger conveyor is an autowalk, it can have an inclined
conveying section (in this case a ramp section). The solution is
most advantageous when the passenger conveyor is an escalator,
because in escalators the inclination angle is steep enough to
cause realistic risk of rushing downwards due to gravity affecting
on the passengers.
[0066] In the illustrated examples the stopping device 9 is
arranged to stop rotation of the nut member 8 and the screw member
is connected with the diverting wheel 4 for being driven by the
diverting wheel 4, and arranged to transmit rotation to the nut
member 8, because this order is simple to implement. However, the
structure could alternatively be inversed such that the stopping
device 9 is arranged to stop rotation of the screw member and the
nut member is connected with the diverting wheel 4 for being driven
by the diverting wheel 4, and arranged to transmit rotation to the
screw member 8.
[0067] It is to be understood that the above description and the
accompanying Figures are only intended to teach the best way known
to the inventors to make and use the invention. It will be apparent
to a person skilled in the art that the inventive concept can be
implemented in various ways. The above-described embodiments of the
invention may thus be modified or varied, without departing from
the invention, as appreciated by those skilled in the art in light
of the above teachings. It is therefore to be understood that the
invention and its embodiments are not limited to the examples
described above but may vary within the scope of the claims.
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